... OD170mm Ring shape with hole High coercive forceNeodymium Ring Magnet with N35,N38,N40,N42,N45,N48,N50, ... coercive force.6, With precise tolerance.Application for NdFeB magnet:Magnetic separator, Sensors, Wind generators,Vibration motors,DC motors, Servo ... ,household appliances,microphone parts,transmission equipments...Features of NdFeB magnet :Neodymium magnets are mainly made from neodymium ,iron, ...